Lepai T-Amp with TA2020 - Page 92 - diyAudio
Go Back   Home > Forums > Amplifiers > Class D

Class D Switching Power Amplifiers and Power D/A conversion

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 16th September 2011, 05:37 AM   #911
diyAudio Member
 
Join Date: Nov 2007
HI from Argentina and first, excuse my poor english...
I have a second edition lepai lp-2020(090210pcb) and I have the sure board with the ta2124 ic too...
well.. the stock lepai sound very good without mods better than my sure-tripath board, but... if You see the photo you will find a very extrange dateail in the inductors... one of them have the value .470 uh i don't have instrumental to measure inductances but both channels sounds very good anyone can explain that?
my main amps are el84 push pull and el84 single ended, my speakers full range fostex fe 206e and a pair of almost good ears (i think)
Attached Images
File Type: jpg Foto0184.jpg (659.4 KB, 206 views)
  Reply With Quote
Old 18th September 2011, 01:27 PM   #912
diyAudio Member
 
Join Date: Sep 2011
Hello everyone I purchased one of these a few weeks ago and have the LP-2020A+
I love it and it would go perfect for my boombox build but 1 thing I am having issues with is the bass, well the lack of bass - I know it has kinds been discussed here but was wondering if anyone managed to find a solution where the over all still sounded good. Would better pot controls make a difference?

Also has anyone managed to bypass the tone, treble and bass controls wile still leaving the volume control working - is this even worth doing, as in does it make a difference in sound quality?

I am also considering adding a mic input which will be active at the same time the music is playing is it best to add something external or can it be done from within the amp?

I hope there not silly questions im new to the world of audio modding and would love to do some worth wile mods to this baby before I install her.

-Thanks

Last edited by Motsey; 18th September 2011 at 01:47 PM. Reason: added more questions lol
  Reply With Quote
Old 18th September 2011, 09:10 PM   #913
nige838 is offline nige838  United States
diyAudio Member
 
Join Date: Dec 2009
Quote:
Originally Posted by Motsey View Post
Hello everyone I purchased one of these a few weeks ago and have the LP-2020A+
I love it and it would go perfect for my boombox build but 1 thing I am having issues with is the bass, well the lack of bass - I know it has kinds been discussed here but was wondering if anyone managed to find a solution where the over all still sounded good. Would better pot controls make a difference?

Also has anyone managed to bypass the tone, treble and bass controls wile still leaving the volume control working - is this even worth doing, as in does it make a difference in sound quality?

I am also considering adding a mic input which will be active at the same time the music is playing is it best to add something external or can it be done from within the amp?

I hope there not silly questions im new to the world of audio modding and would love to do some worth wile mods to this baby before I install her.

-Thanks
No silly questions. I've had 4 different models of the Lepai with TA2020s in them all. This newest one with the tone bypass on the front has problems. THe older lepais had good bass and could really belt it out. These new ones, however, have horrible bass and the whole tone control circuit sucks if you ask me. What's worse, they take it from the input, to the pot, THEN to the 2 opamps and finally to the TA2020. THis makes it much harder to bypass the opamps. If anybody has figured out a way to bypass the opamps, please let me know.
Sorry I couldn't help you more, just wanted to rant for a minute
  Reply With Quote
Old 18th September 2011, 10:20 PM   #914
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
I think I mentioned bypassing everything between the pot and TA2020 in a previous post. It involves inserting a jumper from the pot wiper arms to the capacitors on pins 10 and 13 of the TA2020. And cutting the traces where necessary.
It sure would be nice if someone could post a LP-2020A+ schematic.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 19th September 2011, 05:05 AM   #915
nige838 is offline nige838  United States
diyAudio Member
 
Join Date: Dec 2009
Quote:
Originally Posted by sofaspud View Post
I think I mentioned bypassing everything between the pot and TA2020 in a previous post. It involves inserting a jumper from the pot wiper arms to the capacitors on pins 10 and 13 of the TA2020. And cutting the traces where necessary.
It sure would be nice if someone could post a LP-2020A+ schematic.
Thanks for posting.
If you jump it, wouldn't you loose the tone controls?

Either way, how was the sound?

and

Just to clarify,are you talking about the smd Lepai 2020? (i.e. tone bypass model?)
  Reply With Quote
Old 19th September 2011, 06:55 AM   #916
diyAudio Member
 
Join Date: Oct 2007
Quote:
Originally Posted by sofaspud View Post
It sure would be nice if someone could post a LP-2020A+ schematic.
There were a couple of schematics posted a while back - not sure
it's still the same for the newer models.

Lepai T-Amp with TA2020

Lepai T-Amp with TA2020

Last edited by quadtech; 19th September 2011 at 06:57 AM.
  Reply With Quote
Old 19th September 2011, 07:20 AM   #917
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
Quote:
If you jump it, wouldn't you loose the tone controls?
Yes. My understanding was that is what was being questioned. Bypassing the op amps only may not be a good idea; I think they're being used to provide some gain and buffering for the passive tone circuit. I replaced the stock 4558s with a couple LM833s I had on hand. It wasn't without issues, but I'm running mine with a sub and can't complain (tone defeat set ON). Check out the past couple month's posts for more details.
This is the LP-2020A+ version with SMT parts that I have. The schematics posted already for earlier models are different, but how different I don't really know.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 19th September 2011, 05:33 PM   #918
diyAudio Member
 
Join Date: Sep 2011
Quote:
Originally Posted by sofaspud View Post
Yes. My understanding was that is what was being questioned. Bypassing the op amps only may not be a good idea; I think they're being used to provide some gain and buffering for the passive tone circuit. I replaced the stock 4558s with a couple LM833s I had on hand. It wasn't without issues, but I'm running mine with a sub and can't complain (tone defeat set ON). Check out the past couple month's posts for more details.
This is the LP-2020A+ version with SMT parts that I have. The schematics posted already for earlier models are different, but how different I don't really know.
Do you know if replacing the op amp will make the amp consume more power? I have ordered "2x NE 5532 P Dual Low-Noise Operational Amplifier DIP 8" and will be using my amp in a battery powered boom box so would like the amp to consume as low as battery as possible.

*Also i wanted to know if anyone knows of a place i can buy 6 x "Polypropylene Film Capacitors 0.47uF 450VDC 5%" from with low postage costs as the place i was looking are charging 12 for the postage alone! I want to replace some bits and have but dont want to spend a fortune on n amp like this

Last edited by Motsey; 19th September 2011 at 05:45 PM.
  Reply With Quote
Old 19th September 2011, 07:15 PM   #919
diyAudio Member
 
sofaspud's Avatar
 
Join Date: Nov 2005
Location: San Antonio
Quote:
Do you know if replacing the op amp will make the amp consume more power?
Replacing the 4558s with 5532s will likely mean a little higher current consumption, but it really isn't enough to be concerned about. The difference will be only a small percentage of the total current draw from the battery.
__________________
It is error only, and not truth, that shrinks from enquiry. - Thomas Paine
  Reply With Quote
Old 21st September 2011, 05:49 PM   #920
diyAudio Member
 
Join Date: Sep 2011
Quote:
Originally Posted by sofaspud View Post
Replacing the 4558s with 5532s will likely mean a little higher current consumption, but it really isn't enough to be concerned about. The difference will be only a small percentage of the total current draw from the battery.
I recieved myNE5532's but i got the wrong ones! Duh! Im such a noob and didnt take any notice of the "dip 8" written on the listing

can i still solder these to the board but using wires to connect each leg or is it just not worth it?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
New ta2020 pcb'S ArjenShenzhen Vendor's Bazaar 98 14th November 2012 12:39 PM
Ta2020 Bengali Class D 0 29th September 2007 06:28 AM
Eb-ta2020 opentop Class D 16 30th May 2005 08:42 AM


New To Site? Need Help?

All times are GMT. The time now is 04:34 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2